Burnishing tool



BURNISHING TOOL Filed Sept. 50, 1942 llll Patented June 19, 1945 BURNISHING aTOOL AlfredH. Haberstump, Detroit,'Mich.,' assigner to 'The LMurray`^'Co1"poration 'of America, "Detroit,\-

` p Mih., @corporation of Delaware tArmilication.September 30, 1942. Serial No. 460,319

S'Clams. (0129-90) This;inventionrelates to iburnishingrtools,` and particularly? to .aburnishing tool I for.` ironing metal Vat 'f the *sides of a` scratch lmark; into `the ',scratch cavity, :and l"sealing `and polishing the surface thereafter. l

The present invention-is an improvement on the '.burnishing tool` illustrated, described `and .claimed in ,the `copending `application `of R. D. Stephens,l.Serial No.i459,f417, ledSeptember 23, .1942,andlassignedLto the f assignee of the,l present invention.

rrheburnishing w01 isemployed for niiingfsealv ing, andpolishing the scratchmarks nwhich ap- ,pearinmetal `or otherfmaterial, and particularly in-clad rmeta1employedfas the covering material or skin of airplanes. Thecladqmaterial-hasia rcenterpcore ofaluminum alloyandantouter surrubber, `or .a similarmaterial embodying friction propertiesy `which engagethe metal surface on each side. ofthe scratchJmar'k-for lsteadying the Atooll-and `guiding `.the 'burnishing .head .along the mark. "Thefhead is .disposed in nii-center `rela- .tion ltothe V.'1,Xis..of.`its shank, which tends `.to transfer some of the oscillating .movement to the tool when in contactwitht'he work. The rubber or .similar wheelsgrasp .the surface vof `the sheet andprevent any oscillatingmovement vfrom being transferred from .the burnishing head `to the driving fportionof `the,` tool. .'Thus,` `all of the movement appliedto the'burnishinghead will be utilized `in workingithemetal `on"both sides `of thescratchmaik thereinto and intosealed relation.

Accordingly, the main objects ofthe invention are: "To rprovide atool with a lburnishing head mounted in .offset `relation-izo `the axis `of the tool and with spring-pressed wheels for stabilizingthe toolpperationylto `providerfatool having ya right angled driving head with a burnishing tip which is in olf-center relation to its shank and a springpressed support for a wheel which extends below the burnishing tip; to provide a burnishing tool having 9, head in ofi-center relation to the axis of its shank with a hardened tip of segmental isphericalform; foriworking .theyr metal on `each side gof la scratch m'ark `without undue wear-.to vthe tipa and, in generaLqto provide :a burnishing Itool with` a: pair ,of guiding :and :stabilizing Wheels and with-a hardenedrburnishing tip. Other objects tand features `of novelty of the `invention will fbe feitherspecically pointed I out .orvwill become apparent When referring,` for a betterlunderstanding of-theinvention, to the followin'g description, taken in commotion rwith the accompanying draWing, --Wherein:

fl'igure lfisfa viewin-:elevationbf a burnishing `tool embodyingtfeatures of wthislinvention, -with the `burriishing` tip out `of `contact with `the mark `to be burnished;

Fig.,4 2 ieg-an enalview `.of `the tool illustrated in Fig. -3\is=a broken vview of the` tool Villustrated `inlig. -1,\Wth the-burnishing` tip in engagement with-.the mark; Iand l 4..is abrkenfsectional view of the structurellustrated in Fig.w2, taken on the line '4,-4 thereof. l

"Figure "1 'illustrates a pneumatically 'operated tool 5 of conventional form, having 'a Jdriven collet "16 disposedatright "anglef'to the body portion I thereof. Air or other 'fluid `isJ introduced in'to the body throughf` the inletopening 8 controlle'd "by-a Jl'ever "9 operating la valve stem 1I I. The collet 6 supports thelburnishingtool 1S t2 having a shank I3 and a burnishinghead I4. N'Ihe iaxis .of therhead `I4 is oiiset from the axis of rthe shank @I3 vand `isof segmental, spherical `shape 4sorasto have a; pointengagement with the metal. A.'Ihepoint passesacross the metal at both` sides uof `themark and works Vthe metal into the base fandinto l.sealing relationship.

A bracket I5 islclar'nped tothebody portion `1` .of theltool byacap -IIi` and bolts I1. Thebracketxhasta bifurcated end win-which a Awheel-sup- .por'tingelement ISHis secured on a pivot2`I. `The end 22 upwardly tohave the Wheelsf29 disposed" belowv the burnishing end I4 of the tool in position to engage a sheet 32 to be burnished before the head I4 comes into contact' therewith, as illustrated in Figs. 1 and 2.

Further pressure applied to the body portion I moves the head downwardly against the tension of the spring 24 and applies a predetermined pressure betweenv the wheels 29 and the surface of the sheet 32. Sufficient friction will then exist between the wheels 29 and the surface to prevent the'movement of the eccentric end I4 from oscillating the tool body during the burnishing operation. The wheels, besides stabilizing the tool, assist in guiding the head III backwardly and forwardly along the scratch mark as the burnishing operation progresses.

A felt roller 34 mounted on a bushing 35 is secured on a shaft to the extensions 36 of the arms 2l in position to engage the sheet 32 when the tip I4 engages the scratch mark. Lubricating material is carried by the felt roller which provides lubrication to the mark and tip to prevent the gouging of metal by the tip and the wearing of its point.

The degree of eccentrcity of the head I4 to the axis of the tool shank I3' may be Varied in diierent tools, depending upon the width of the scratch marks or the width of the path to be burnished. In Fig. 4, a section of the burnishing head I2 is illustrated with the shank portion I3 made of mild steel or similar material while the tip portion I4 secured thereto is made of extremely hard material, such as Stellite, tungsten, and the like. The hardened tip sube stantially. eliminates any wear to the end of the tool and materially increases the tools life.

When a scratch mark 33 is to be burnished, the wheels are disposed upon the sheet 32 equally spaced on either side of the mark. This will align the axis of the shank I3 with the mark so that the eccentric point of the tip I4 will travel beyond both sides of the mark.v The tool is then pressed downwardly to have the bunishmg tip Id engage the surface of the sheet and, when rotated at high speed, on the order of 5,000 R. P. M., the material at the sides of the scratch will' be worked into the base of the scratch and into sealed relation. Thereafter, the surface may be polished by the application of light pres-- sure to the tool as the tool is moved back and forth across the mark as it is guided bythe wheels. It was found that a light scratch mark can be completely burnished by the tool from the sheet and polished in the course of one to two minutes operation.

What is claimed is:

1. A burnishing tool having a tip mounted in offset relation with its shank, a spring-pressed wheel extending beyond the tip for guiding and stabilizing the tool during operation, and means for driving said tool in rotation about the axis of the shank to have the burnishing point of the tool describe a circle thereabout.

2. In a burnishing device, a driven tool supporting element, a tool supported by said element having a burnishing end mounted eccentrically to the center of the tool shank, a bracket on said device, an element pivoted on said bracket extending adjacent to the tip, a wheel on the end of the element projecting below the tip, and a spring urging said wheel away from the tip to have the wheel engage the surface of the material with a predetermined pressure when the tool engages said surface.

3. A burnishing device including, in combination, a driving element, a driven element, a

burnishing tool supported by said driven element 1 having a head in eccentric relation to the axis of the tool shank, a bracket supported on said driving element, a bifurcated member pivoted on the bracket, a pair of spaced wheels supported on the bifurcated end of the saidk member disposed on opposite sides of the yburnishing head, a spring on the opposite end of said member for urging Said wheels below the burnishing head, and means for controlling the operation of the driving element.

4. In a burnishing device, a driving portion, a driven portion disposed at right angle thereto, a burnishing tool supported by said driven portion, a bracket on said driving portion, a bifurcated element pivoted on. said bracket, wheels disposed in the bifurcated end of said element on opposite sides of said burnishing tool, and a spring on the opposite end of said element in position to move the end of the element supporting the wheels downwardly to have the wheels disposed below the end of the burnishing tool.

5. A burnishing device including a 'driving portion, a portion driven thereby, a burnishing tool driven by said driving portion, said burnishing tool having a head in o-center relation to the axis of its shank which is made of a material lharder than the shank portion for worky ing the metal on both sides of a cavity toward the center thereof.

6. The method of burnishing the metal at the sides of scratch marks which includes the steps of working the metal at the sides of the mark toward the center by a point rotating in a circle across the mark, and guiding the burnishing operation by frictionally engaging the lsurface outwardly of the mark during theburnishing operation.

'7.y The method of burnishing a scratch mark which includes the steps of, rotating a point across the sides of the mark, and stabilizing the operation and guiding the movement of the po-ints along the mark by frictionally engaging the surfaces on both sides of the mark with a predetermined pressure.

` 8. A burnishing tool having a tip mounted in offset relation to its shank, means for rotating said shank, a spring pressed wheel extending beyond the tip for guiding and stabilizing the tool when the tip is operating on the surface of a sheet, and alubricating element contacting said'sheet adjacent to saidtip.

9. In a burnishing device; a driven tool `supporting element, a tool supported by said element'having a burnishing end mounted eccentrically to the center of the tool shank,.a bracket on said device, a member pivoted on said bracket extending adjacent to the tip, a wheel on. the end of said member, a lubricating roller also mounted on said member, and aspring urging said Wheel and roller away from the tip to have the wheel and roller engage the surface of the material with a predetermined pressure when the burnishing end of the tool engages said surface.

ALFRED I-I. HABERSTUMP. 

